6.1-stable review patch. If anyone has any objections, please let me know.
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From: Ard Biesheuvel ardb@kernel.org
commit 00c6b0978ec182f1a672095930872168b9d5b1e2 upstream.
There is no need to defer the assignment of the paging related global variables 'pgdir_shift' and 'ptrs_per_p4d' until after the trampoline is cleaned up, so assign them as soon as it is clear that 5-level paging will be enabled.
Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Link: https://lore.kernel.org/r/20230807162720.545787-9-ardb@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/boot/compressed/misc.h | 2 -- arch/x86/boot/compressed/pgtable_64.c | 14 +++++--------- 2 files changed, 5 insertions(+), 11 deletions(-)
--- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -170,9 +170,7 @@ static inline int count_immovable_mem_re #endif
/* ident_map_64.c */ -#ifdef CONFIG_X86_5LEVEL extern unsigned int __pgtable_l5_enabled, pgdir_shift, ptrs_per_p4d; -#endif extern void kernel_add_identity_map(unsigned long start, unsigned long end);
/* Used by PAGE_KERN* macros: */ --- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -130,6 +130,11 @@ struct paging_config paging_prepare(void native_cpuid_eax(0) >= 7 && (native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31)))) { paging_config.l5_required = 1; + + /* Initialize variables for 5-level paging */ + __pgtable_l5_enabled = 1; + pgdir_shift = 48; + ptrs_per_p4d = 512; }
paging_config.trampoline_start = find_trampoline_placement(); @@ -206,13 +211,4 @@ void cleanup_trampoline(void *pgtable)
/* Restore trampoline memory */ memcpy(trampoline_32bit, trampoline_save, TRAMPOLINE_32BIT_SIZE); - - /* Initialize variables for 5-level paging */ -#ifdef CONFIG_X86_5LEVEL - if (__read_cr4() & X86_CR4_LA57) { - __pgtable_l5_enabled = 1; - pgdir_shift = 48; - ptrs_per_p4d = 512; - } -#endif }